I need to fasten a 1″ thick fireplace surround to my fireplace. I’ve never had too much luck with those tapcon screws, or with the lead shields. They seem to almost always pull out on me. Also, the fasteners need to be countersunk, so I need to keep them relatively small; #8 or #10 at the largest. What I’m thinking about doing is drilling a 1/2″ hole in either brick or mortar where ever I need to land a fastener and fill it with thickened epoxy. Once the epoxy cures, I’ll drill a pilot hole through the wood and into the epoxy “plug” and drive a screw into it. I’ve also thought of gluing an oak plug into the hole. Any thoughts?
None of this will be anywhere that will get hot enough that it should affect the epoxy. The screws don’t need to support any weight, they just need to hold the thing tight to the wall.
Edited 10/13/2006 4:02 pm ET by Quickstep
Replies
Gluing in an oak dowel is the way I have done it many times. I use this method for attaching handrails against stone or brick wall too.
If you size the hole tightly enough, you can use construction adhesive instead of epoxy, and when you drive in the screw, it will expand the dowel solidly against the insides of the hole.
The dowel should fit tightly enough that you have to drive it in. The construction adhesive will lubricate it a bit for the drive, then in about an hour you can put a screw in it.
Make sure that you don't put too much adhesive in the hole before you insert the dowel or you will learn a bit about hydraulics.
Don't forget to make sure there is no dust in the hole!
Hal
http://www.rivercitywoodworks.com
Edited 10/13/2006 4:56 pm ET by Hal J
Quickstep,
I was in the fastener business for a number of years and can quote chapter and verse on the pros and cons of fastener systems / products / etc. ad nausuem infinium. This aside, Hal J’s suggestion (oak dowel w/ a dab of adhesive) makes good sense to me. A number 9 coarse thread drywall screw (gasp!) should give you a good bite into the dowel endgrain.
I think you will have a hard time getting the epoxy to fill the hole and not drip out. A solid chunk of epoxy might fracture. I'm surprised you have difficulty with Tapcons and lead shields. The tapcons are available in a number of sizes and head configurations, including phillips flat heads that are easy to plug or cover with a molding. The pilot hole has to be the correct size, deep enough, clean and lubricating the screw helps. I always use a mortar joint, not the brick but bricks are hard in my area. The same is true for the shields, I also hit the mortar joints with these but I use a minimum of 1/4" bolt. Having the right length is important, bottoming out will extract the shield. A hammer drill makes drilling quick. Wood plugs work but you need to make sure they won't shrink and get loose. You'll be done in a few minutes with Tapcons. You won't even have to move the mantle or wait for things to dry. Place, drill and attach.
Beat it to fit / Paint it to match
I'm with you hammer. I've never had problems with Tapcons. The only time I've heard of issues is when the wrong size pilot drill was used, or it wasn't drilled deep enough into the masonry, causing the screw to bottom out and break.
Jeff
For applications such as yours, I would use a lead mollie, the size that requires a 1/4" hole.
As hammer suggested, drill into the mortar joint. To snug up the mollie, I always pound in slivers of wood around the mollie; round toothpicks broken in half work especially well.
I think the mollies would be more reliable than dowels, since you'd be screwing into the end grain of the dowel.
********************************************************
"It is what we learn after we think we know it all, that counts."
John Wooden 1910-
The reason the dowel works so well is because the screw is going into endgrain. This way it almost splits the dowel, but because of the solid brick hole that the dowel is in, the dowel can't split, but instead expands and becomes wedged tightly in the hole.
I have used lead molys too, and think they work pretty well. I wouldn't recomend against their use, in fact either way works very well. But there is something sort of organic about using the dowel. By the way, I prefer to use white oak dowels for this. I usually use a dowel a size larger than the hole I drill, then whittle the dowel down to a really tight fit using a block plane.
Hal
http://www.rivercitywoodworks.com
I take your point.......I've worked in old houses where they used dowels in the manner you suggest. So it certainly is a tried and true method. I just like those lead mollies. :)********************************************************
"It is what we learn after we think we know it all, that counts."
John Wooden 1910-
nikkiwood,
I know it too! They are quick and easy, and are pretty cool the way they work.
It's the drilling that is a drag!
Hal
the wood whistle is definately one way to go. proper alignment becomes the problem...you almost need to drill your holes in your surround...put it in place...mark the locations of the holes on teh brick...move it back out of the way...dril the holes...insert the whistles...wait for the epoxy to dry...put back the surround...pilot dill the whistles...insert your screws....plug the screw holes...not hard if the surround is small, but a pain if moving it around is difficult...
not sure how brittle your brick is, but if it's pretty solid you can just drill a hole a little bit larger than the shaft of the screw and use weed-eater string...put the surround in place...drill through the surround into the brick with a bit a little larger in diameter than the screw threads....counterbore each hole in the surround for your plugs...take a short (maybe 6") length of weed-eater string or copper wire, or similar....push one end of it all the way back into the back of the hole while holding onto the other end...drive the screw into the hole...clip off excess string...plug hole...
the string acts as a wedge in the hole preventing the screw from pulling out...believe it or not it is actually very strong....
Hold the phone! Who said anything about plugs in the surround? Nothing larger than a brad should show, or at the most a 5d or 6d finish nail, which could be filled to be invisible.
If you don't read the books on fireplace mantles that are all the rage now, and figure it out for yourself instead, there are almost always ways to do things without the fasteners showing.
Hal
http://www.rivercitywoodworks.com
the original poster made it sound like his only option was to screw the assembly to the wall...
I agree a better way to do it would be to construct the surround so that you were fastening a cleat to the wall with screws and then using blind fasteners or nails to secure the surround to the cleats...but the surround would need to be constructed with this type of fastening in mind....
nail holes are sure easier to deal with than plugging screw holes....
Nail holes are certainly easier to deal with than plugs, but I don't find plugs to be that difficult. I cut plugs form the same species, glue them in, pare them flush with a chisel, then paint. It's more steps than puttying a bad hole, but not a lot.
All,
And leaving a strip of molding, or pilaster face, loose til after installation, then applying it over the screws, eliminates the need to plug at all.
Regards,
Ray Pine
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